Input: ads7846: Add description how to use internal reference (ADS7846)

By simply setting vref-mv to 0 the internal reference will be used.
Document that!

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt
index 33a1638b61d6bb950b45f0b14ceccaf7ff58eb19..c6cfe2e3ed4119f4d4831312b962b47cd7009c85 100644 (file)
--- a/Documentation/devicetree/bindings/input/ads7846.txt
+++ b/Documentation/devicetree/bindings/input/ads7846.txt
@@ -29,6 +29,8 @@ Optional properties:
        ti,vref-delay-usecs             vref supply delay in usecs, 0 for
                                        external vref (u16).
        ti,vref-mv                      The VREF voltage, in millivolts (u16).
+                                       Set to 0 to use internal refernce
+                                       (ADS7846).
        ti,keep-vref-on                 set to keep vref on for differential
                                        measurements as well
        ti,swap-xy                      swap x and y axis